Differential horn



Sept. 21, 1965 D. VRSALJKO DIFFERENTIAL HORN Filed March a, 1964 I 0 MM Pm 1 W 0 k .m 2 D M 0 W :M M

m 3 V a u a 9 4 I i 2 m m United States Patent 3,207,123 DIFFERENTIAL HORN Dinko Vrsaljko, Split, Yugoslavia, assignor to Kockums Mekaniska Verkstads ALB, Malmo, Sweden, a Swedish joint-stock company Filed Mar. 6, 1964, Ser. No. 350,132 Claims. (Cl. 116142) The present invention relates to a pressure-gas operated born the inlet of which is surrounded by a valve seat which in turn is surrounded by an annular pressure-gas inlet and against which a valve member can be periodically pressed by movement toward and away from the valve seat in a chamber of an apparatus housing.

In prior-art horns of this type an elastic diaphragm has been used as an oscillating pressure-gas control means, and during the operation of the horn said diaphragm performed oscillations involving an elastic deformation of the diaphragm. Both the mass of the diaphragm as well as the elasticity thereof has thus been factors determinative of the function of the diaphragm. However, the prior-art horns of this type suffer from certain drawbacks which are overcome or considerably reduced by the present invention.

Thus, one object of the invention is to provide a pressure-gas operated horn which functions reliably within a wide range of temperatures and pressure-gas used to operate the horn, for instance steam or compressed air;

Another object of the invention is to provide a pressuregas operated horn which starts easily and does not require readjustments for preserving its starting and sounding properties.

A further object of the invention is to provide a pressure-gas operated horn which reliably starts to sound on its fundamental frequency and has no tendency to start sounding on a harmonic.

Yet another object of the invention is to provide a pressure-gas operated horn in which the vibrating member does not sufier from fatigue due to elastic deformation.

These and further objects and features of the invention will become apparent from the following description in which reference is made to the accompanying drawing which illustrates an embodiment chosen by way of example.

In the drawing:

FIG. 1 is a side elevational view of the horn according to the invention;

FIG. 2 is a sectional view on a larger scale on line IIII in FIG. 1.

The horn illustrated in the drawing has a horn 1 of customary type, which has an inlet portion 2 in an apparatus housing 3. The inlet is surrounded in the apparatus housing by a plane annular relatively narrow pressure-gas inlet 5. Said pressure-gas inlet 5 communicates via an annular passage 6 with a connecting passage 7 for the connection of a conduit (not shown) to a pressure-gas source (not shown), e.g., an air compressor or steam generator. The annular pressure-gas inlet 5 is surrounded by a second valve seat 8 which is considerably (preferably several times) broader than the valve seat 4 and is coplanar therewith.

The valve seats 4 and 8 in the apparatus housing 3 constitute one end wall of a chamber 9 in the apparatus housing 3, while the other end wall of the said chamber is formed by a'cover 10 attached to the apparatus housing. Loosely placed in the relatively fiat chamber 9 between the valve seats 4 and 8 on one hand and the cover 10 on the other is a valve member in the form of a rigid disk 11. On the side facing away from the inlet 2 of the horn said disk 11 is provided with a central proice jection 12 extending into a central recess 13 in the cover 10. Said recess 13 forms a guide for the projection 12, implying that the disk 11 is mounted so that it is freely movable toward and away from the seats 4, 8 and the cover 10, respectively, but cannot perform any appreciable movements in parallel with the plane of the seats 4 and 8.

In the position shown in FIG. 2 the valve disk 11 is in sealing application with both the broad seat 8 and the narrow seat 4, and within the area of the broad seat 8 the disk 11 is provided on the side facing the said seat with preferably annular grooves 14. The part of the chamber 9 which is separated from the inlet 2 of the born 1 by the valve disk 11 when the latter is in application against the seats 4, 8, may have a connection with the atmosphere of the type exerting a throttling action upon the flow of gas during the movement of the valve disk 11. This connection may be realized in that one narrow hole 15 is made in the side wall of the apparatus housing 3 encircling the chamber 9, as shown in FIG. 2, or in the cover 10. Alternatively or additionally the valve disk 11 may be provided with a connection between the inlet 2 of the horn and that part of the chamber 9 which is separated from said inlet 2 by the valve disk 11 when the latter is in application against the seats 4, 8 said connection exerting a throttling action upon the flow of gas during the movement of said disk 11 and being constituted by one through hole 16 in said disk.

When pressure gas is supplied to the passage 6 while the valve disk 11 is in application against the seats 4, 8, as shown in FIG. 2, the pressure of the gas on the valve disk 11 in the area of the pressure-gas inlet 5 will urge the rigid valve disk 11 toward the cover 10. This allows pressure gas to flow into the inlet 2 of the horn 1 between the valve disk 11 and the narrow seat 4 so that a pressuregas shock is produced in the horn inlet 2. Simultaneously the pressure gas is allowed to flow between the broad seat 8 and the valve disk 11 toward the part of the chamber 9 between the valve disk and the cover 10. Having acted upon the valve disk 11 only within the small surface in the area of the pressure-gas inlet 5, the pressure gas thus is given the possibility, when the disk is moved away from the valve seats 4, 8, of acting over the entire one side of the disk 11, with the result that the valve disk is heavily accelerated and the pressure-gas shock in the horn inlet 2 will undergo a very steep increase in force. The major portion of the pressure gas flows from the pressure-gas inlet 5 to the horn inlet 2 while the flow of the pressure gas between the valve disk 11 and the valve seat 8 will be relatively small by reason of the large throttling action between the broad valve seat 8 and the valve disk 11 and above all by reason of a counterpressure from the gas in the chamber 9 between the valve disk 11 and the cover 10, which gas is compressed by the valve disk 11 when the latter moves away from the valve seats 4, 8. The movement of the valve disk 11 away from the valve seats 4, 8 under the action of the pressure gas entering through the pressure-gas inlet 5 is initially counteracted only by the mass of the valve disk 11 and the compression of the gas in the chamber 9 between the valve disk and the cover 10, but the pressure-gas shock produced in the inlet of the horn 1 will give rise to a pressure wave travelling toward the mouth of the horn 1. The pressure Wave is followed by a depression wave which actuates the valve disk 11 whereby the direction of movement thereof is reversed under the effect of said depression wave and the pressure of the said compressed gas between the valve disk 11 and the cover 10 so that the valve disk 11 is again very rapidly pressed into application against the valve seats 4, 8. When the amplitude of the depression wave adjacent the valve disk 11 in the horn inlet 2 has diminished or has been converted into a pressure increase the pressure gas in the pressure-gas inlet 5 is able again to unseat the valve disk 11 from the valve seats 4, 8, wherafter the described cycle is repeated. There are thus obtained in the horn inlet 2 a series of pressure-gas shocks having a frequency wholly determined by the fundamental frequency of the horn 1. Those portions of the pressure waves in the horn 1 produced by the pressure-gas shocks which are not reflected at the horn mouth 1 radiate into the atmosphere as a sound having the fundamental frequency of the horn 1.

Having a heavy throttling action on the gas flow, the hole 15 and/or 16 in FIG. 2 has no appreciable effect on the above described function of the horn, but said hole 15 and/or 16 is of importance to an easy starting of the horn immediately after a prior sound emission. During operation of the horn the mean pressure in the chamber 9 between the valve disk 11 and the cover 10 will be slightly higher than the pressure of the free atmosphere. Should there be no hole and/ or 16, this would imply that the valve disk 11 upon interruption of the operation of the horn would be kept pressed against the valve seats 4, 8 by the excess pressure in the chamber 9 so that the pressure gas, when again supplied to the pressuregas inlet 5 to start the horn, would have difficulty in urging the valve disk 11 away from the valve seats. The hole 15 and/or 16 prevents the excess pressure from remaining in the chamber 9 between the valve disk 11 and the cover 10 after interruption of the operation of the horn in that it permits a slow gas flow from the chamber to the atmosphere either directly through the hole 15 or indirectly through the horn 16 and the horn 1.

I claim:

1. A pressure-gas operated horn, comprising a housing enclosing a chamber, a horn connected to said housing, a first valve seat on the inlet end of said horn, said first valve seat facing the chamber in said housing, means defining an annular pressure-gas inlet to the chamber in said housing, said inlet surrounding said first valve seat, a second valve seat in said housing, said second valve seat facing the chamber in said housing and surrounding said annular inlet and said first valve seat, said second valve seat being considerably broader than said first valve seat, and a rigid disk freely movable toward and away from said first and second valve seats in the chamber of said housing so as to alternately seal the annular pressuregas inlet from the chamber in said housing and said horn and erect communication from the annular pressure-gas inlet to the chamber in said housing and said horn between said disk and said first and second valve seats.

2. A horn according to claim 1, comprising means defining annular grooves in the surface area of said disk opposite said second valve seat.

3. A horn according to claim 1, comprising means on said disk defining a throttling connection between the chamber in said housing and the inlet of said horn when said disk is in engagement with said first valve means around the inlet of said horn. i

4. A horn according to claim 1, comprising means on said housing defining a throttling connection between the chamber in said housing and the atmosphere.

5. A pressure-gas horn, comprising a housing enclosing a chamber, a horn connected to said housing, a first valve seat on the inlet end of said horn, said first valve seat facing the chamber in said housing, means defining an annular pressure-gas inlet to the chamber in said housing, said inlet surrounding said first valve seat, a second valve seat in said housing, said second valve seat facing the chamber in said housing and surrounding said annular inlet and said first valve seat, said second valve seat being considerably broader than said first valve seat, a rigid disk in the chamber of said housing, and guide means on said disk and said housing guiding said disk for free movement towards and away from said first and second valve seats so as to alternately seal the annular pressure-gas inlet from the chamber in said housing and said horn and erect communication from the annular pressure-gas inlet to the chamber in said housing and said horn between said disk and said first and second valve seats.

References Cited by the Examiner UNITED STATES PATENTS 1,043,032 10/12 Richards 116142 1,085,354 1/14 Mukautz 116--142 1,698,296 1/29 Brandegger 116142 3,117,552, 1/64 Swanson 116142 LOUIS I. CAPOZI, Primary Examiner. 

1. A PRESSURE-GAS OPERATED HORN, COMPRISING A HOUSING ENCLOSING A CHAMBER, A HORN CONNECTED TO SAID HOUSING, A FIRST VALVE SEAT ON THE INLET END OF SAID HORN, SAID FIRST VALVE SEAT FACING THE CHAMBER IN SAID HOUSING, MEANS DEFINING AN ANNULAR PRESSURE-GAS INLET TO THE CHAMBER IN SAID HOUSING, SAID INLET SURROUNDING SAID FIRST VALVE SEAT, A SECOND VALVE SEAT IN SAID HOUSING, SAID SECOND VALVE SEAT FACING THE CHAMBER IN SAID HOUSING AND SURROUNDING SAID ANNULAR INLET AND SAID FIRST VALVE SEAT, SAID SECOND VALVE SEAT BEING CONSIDERABLY BROADER THAN SAID FIRST VALVE SEAT, AND A RIGID DISK FREELY MOVABLE TOWARD AND AWAY FROM SAID FIRST AND SECOND VALVE SEATS IN THE CHAMBER OF SAID HOUSING SO AS TO ALTERNATELY SEAL THE ANNULAR PRESSUREGAS INLET FROM THE CHAMBER IN SAID HOUSING AND SAID HORN AND ERECT COMMUNICATION FROM THE ANNULAR PRESSURE-GAS INLET TO THE CHAMBER IN SAID HOUSING AND SAID HORN BETWEEN SAID DISK AND SAID FIRST AND SECOND VALVE SEATS. 